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Geopolymer

About: Geopolymer is a research topic. Over the lifetime, 6776 publications have been published within this topic receiving 157991 citations. The topic is also known as: geopolymers.


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Journal ArticleDOI
TL;DR: In this article, a porous red mud (RM) based geopolymers were developed and evaluated to ensure prolonged pH control, including buffering ability, alkalis leaching behaviour, mineralogical composition, microstructure and physical properties.

85 citations

Journal ArticleDOI
TL;DR: In this article, the efficiency of alkaline fusion method to enhance the geopolymeric reactivity of phosphate mine tailings was investigated by XRD measurement, and the microstructure as well as the mechanical behavior of prepared geopolymer mortars were investigated using compressive strength test and EDS/SEM analysis.
Abstract: The present study investigates the efficiency of alkaline fusion method to enhance the geopolymeric reactivity of phosphate mine tailings. The effect of sodium hydroxide content and fusion temperature on the mineralogical composition of the fused phosphate sludge was assessed by XRD measurement. The microstructure as well as the mechanical behavior of the prepared geopolymer mortars were investigated using compressive strength test and EDS/SEM analysis. Furthermore, the thermal stability of samples was studied by measuring the mechanical properties after exposure to several cycles of heat treatment at different elevated temperatures (350, 500, 650 and 800 °C). The obtained results showed that the structure of phosphate sludge underwent a significant variation after fusion. Alkali thermal treatment led mainly to the decomposition of illite, palygorskite and dolomite, and the formation of Na-rich crystalline phases. NaOH content as well as temperature of fusion has been proved to be essential factors controlling the transformations of the material structure and hence the development of the geopolymer strength. The optimum conditions of fusion were set at 10 wt% of NaOH and a temperature of 550 °C, providing geopolymer mortars with high compressive strength (40 MPa).

85 citations

Journal ArticleDOI
TL;DR: The results showed that the sodium-based activator composed of sodium hydroxide and sodium silicate solutions, with a SiO2/Na2O ratio of 3.22, was the most effective activator, providing appropriate workability and extrudability, along with reasonable strength and a high shape retention ability.
Abstract: Since the initial introduction of geopolymers, these materials have been characterised as environmentally-friendly sustainable substitutes for ordinary Portland cement (OPC). There is a routine increase in the application of geopolymers, especially in advanced technologies. Because of its better rheological characteristics compared to OPC, geopolymers are appropriate materials for extrusion-based 3D printing technologies. This paper focuses on the optimisation of an ambient temperature cured geopolymer for 3D printing construction applications. The effects of mixture parameters, including the type of hydroxide solution (HS), the type of silicate solution (SS) and the mass ratio of SS to HS on the workability, extrudability, shape retention ability and mechanical performance of different geopolymer mixtures were investigated. Accordingly, an optimum mixture was identified for geopolymers cured at ambient temperatures. Mechanical properties of the optimised mixture, including flexural and compressive strengths, were measured in different directions with respect to the printed layers. Further, uniaxial tension tests were also conducted on the optimised mixture to measure its interlayer bond strength. The results showed that among the activators investigated, the sodium-based activator composed of sodium hydroxide and sodium silicate solutions, with a SiO₂/Na₂O ratio of 3.22, was the most effective activator, providing appropriate workability and extrudability, along with reasonable strength and a high shape retention ability. The acquired mechanical properties exhibited anisotropic behaviour in different testing direction. The strength of the interlayer bond was found to be adequate to avoid interfacial shear failure.

85 citations

Journal ArticleDOI
TL;DR: In this article, clinker-free cementitious binders were synthesized to produce ambient temperature cured pervious concrete of high aggregate-to-binder ratio, which achieved better mechanical properties and water permeability than cement pervious concretes.

84 citations

Journal Article
TL;DR: In this article, studies carried out on the behaviour of room temperature cured reinforced reinforced GPC flexural members are reported, which showed that the load carrying capacity of most of the GPC beams was marginally more than that of the corresponding conventional OPCC beams.
Abstract: Efforts are urgently underway all over the world to develop environmentally friendly construction materials, which make minimum utility of fast dwindling natural resources and help to reduce greenhouse gas emissions. In this connection, Geopolymers are showing great potential and several researchers have critically examined the various aspects of their viability as binder system. Geopolymer concretes (GPCs) are new class of building materials that have emerged as an alternative to Ordinary Portland cement concrete (OPCC) and possess the potential to revolutionize the building construction industry. Considerable research has been carried out on development of Geopolymer concretes (GPCs), which involve heat curing. A few studies have been reported on the use of such GPCs for structural applications. In this paper, studies carried out on the behaviour of room temperature cured reinforced GPC flexural members are reported. A total of eighteen beams were tested in flexure. Three conventional concrete mixes and six GPC mixes of target strength ranging from 17 to 63 MPa and having varying combinations of fly ash and slag in the binder phase were considered. The reinforcement was designed considering a balanced section for the expected characteristic strength. All the specimens were tested under two-point static loading. The studies demonstrated that the load carrying capacity of most of the GPC beams was in most cases marginally more than that of the corresponding conventional OPCC beams. The deflections at different stages including service load and peak load stage were higher for GPC beams. However, the ductility factor was comparable to that of OPCC beams. The studies showed that the conventional RC theory could be used for reinforced GPCC flexural beams for the computation of moment capacity, deflection, and crack width within reasonable limits.

84 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,059
20221,744
2021990
2020891
2019752
2018658